Regarding methods for producing optically active amino compounds using transaminases, there are many reports concerning methods for producing α-amino acid, but there are few reports concerning methods for producing optically active amino compounds other than α-amino acid. In recent years, a transaminase that generates optically active amino compounds other than α-amino acid has been discovered, and the use thereof for a general method for efficiently producing optically active amino compounds is expected.
However, transaminases known to date for generation of optically active amino compounds other than α-amino acid have had many problems (Non-patent Document 1).
For example, conventional transaminases are problematic in that they have low resistance to water-soluble organic solvents and the half-life of the enzyme activity decreases from about 5 hours to 3.5 hours or less when 10% v/v methanol, THF or DMF is added.
Among optically active amino compounds other than α-amino acid, a transaminase that generates (S)-1-benzyl-3-aminopyrrolidine, that is, a particularly useful pharmaceutical intermediate with high optical purity of 93% e.e. or more, has remained undiscovered (Patent Documents 1 and 2 and Non-patent Document 2).